The trust previously raised $29m to build the Vodafone Events Centre so he's confident the target can be reached.

Construction on the whitewater rafting centre will begin at the end of the year and it's hoped it will be open by the end of 2015.

"We definitely want to have it open for the World Master's Games in 2017, which is the largest multisport event in the world," Mr Jeffery says.

The former Manukau City Council granted the project a 10-year resource consent just before the Auckland super-city was formed.

A revised concept design has just been completed and the centre is now planned to have two whitewater rafting courses - one for recreational rafting and international kayaking events and one for use by school groups. An art gallery, cafe and classroom spaces are also planned.

The trust's business plan shows it will be able to admit 15,000 students every year, Mr Jeffery says.

Counties Manukau Sport will provide a $100,000 annual grant to subsidise entry fees for children from South Auckland.

Mr Jeffery says the trust is "very grateful" for the support it's received from the area's local boards and from the community as a whole.

"The timing's fantastic to get the project underway just before the economy bounces back."